
class Container {

    static of(value) {
        return new Container(value)
    }

    constructor(value) {
        this._value = value
    }

    map(fn) {
        return Container.of(fn(this._value))
    }

}
class Maybe {

    static of(x) {
        return new Maybe(x)
    }

    isNothing() {
        return this._value === null || this._value === undefined
    }

    constructor(x) {
        this._value = x
    }

    map(fn) {
        return this.isNothing() ? this : Maybe.of(fn(this._value))
    }

}
module.exports = { Maybe, Container }